Differential tension control device for automatic multi-needle quilting machines



Oct. 24, 1967 P. KUHN 3,348,507

DIFFERENTIAL TENSION CONTROL DEVICE FOR AUTOMATIC MULTINEEDLE QUILTING MACHINES Filed Aug. 17, 1964 v JNVENTOR, H64 5 Poul Kuhn,

ATTORNEY.

United States Patent York Filed Aug. 17, 1964, Ser. No. 390,018 8 Claims. (Cl. 112118) The present invention relates to automatic multi-needle sewing machines for quilting and more particularly to an attachment therefor whose principal object is to avoid distortion of the design which heretofore occurred while sewing straight stitch lines across the work. The use of this attachment accomplishes perfect cornering as for eX- ample is necessary where the entire design sewn is a meshform of squares or rectangles made by spaced straight stitch lines along the Work, intersected by spaced straight stitch lines across the work. Heretofore, perfect cornering as it is called in the trade, occurred by sheer accident.

The quilting machines for which this attachment is made, essentially include a frame on which a vertically reciprocable horizontal bar has the needles depending therefrom in a coplanar, spaced relation thereon. Under this needle-holding bar, a work-holding carriage is mounted on said frame for movement along the line of .said bar. Said carriage carries pinch rollers beyond the movement and pinch roller operation. Hence, for each needle to make a straight line of stitches along the work, the carriage is at rest while the pinch rollers operate and for each needle to make a line of stitches straight across the work, the carriage is moved in a transverse direction while said pinch rollers are at rest. This invention is principally concerned with the control of the work while straight stitch lines are being sewn across the work. This invention is not concerned With the operation of the machine when the carriage and the pinch feed rollers move simultaneously to effect various designs.

It is evident that in these machines, a tension in the work plies while sewing straight stitch lines along the work, is caused by the pull given thereto by the moving pinch rollers while the rotation of the supply rolls is retarded. This tension is relaxed when sewing is done across the work, hence a distortion results in the design. So for one practice'of this invention, I provide means to maintain the top ply taut while sewing straight stitch lines across the work, by applying an adjustable force to 'turn its supply roll to wind up from each start to each finish of straight line stitching across the work. The application of this force may be afforded by a motor on the carriage, operating a gear train in which an adjustable slip coupling is interposed; one terminal gear of said gear train being on the motor shaft and the other on the shaft of the top plys supply roll. A switch in the circuit of said motor is controlled by a cam on the cam shaft of the machine.

In the accompanying drawing forming part of this specification, similar characters of reference indicate corresponding parts in all the views.

FIG. 1 is a fragmentary front view of an automatic quilter equipped with a preferred embodiment of this invention.

FIG. 2 is a fragmentary top plan view of the cam shaft included in this machine.

FIG. 3 is an enlarged fragmentary perspective view which is partly diagrammatic, showing my attachment on the machine.

FIG. 4 is a fragmentary surface view of a piece of work made by the machine using my attachment.

FIG. 5 is a similar view showing the work done, without the attachment. 4

FIG. 6 is a diagram of the motor circuit which is included in the attachment.

In the drawing, the numeral 15 designates generally an automatic quilter on whose frame 16 is a vertically reciprocatable horizontal bar 17 from which a series of coplanar needles 18 depend in spaced relation along such bar 17. Under this needle-holding bar, a work-holding carriage indicated generally by the numeral 19, carries the rotatable pinch rollers 20, 20' beyond the needles, to feed the work through the machine past said needles. From supply rolls 21, 22 on the carriage, an upper ply 21' and a lower ply 22' are fed through the machine with a layer of batting or wadding 23 between them. Said intermediate layer is from oif a supply roll, not shown, on the frame 16. A camshaft 24 journalled on the machine frame, carries cam means for the control of carriage movement and pinch roller operation. For each needle to make a straight line of stitches S along the work, the carriage 19 is at rest While the pinch rollers 20, 10 turn to feed the work. For each needle to make a straight line of stitches 8' across the work, said carriage is moved in one direction while said pinch rollers are at rest. This class of multi-needle sewing machinery of which the Boettcher Patent No. 1,948,876 is an example, being well known in the art, I have shown only such part thereof as will enable me to explain the use therewith, of my attachment indicated generally by the numeral 25.

The mechanism 25 is mounted on the carriage 19, to one side of the work, and it consists of a motor 26 driving a gear system in which an adjustable slip coupling indicated generally as 27, is interposed; one terminal gear 28 of said gear system, being secured on the shaft 26' of the motor 26 and the other terminal gear 29 of said gear train, being secured at an end of the shaft 30 of the upper ply supply roll 21. The numeral 25 designates a shaft which is parallel to the shaft 37, and is journalled on the plate 42. This shaft 25 has fixed thereon the gear 34' in meshed engagement with the gear 34, and also a crown gear 28' in meshed engagement with the gear 28. The rotation of the motor is such that it will turn the supply roll shaft 30 in the direction to wind up the roll 21. The motor circuit 31 is controlled by a suitable cam 32 on the shaft 24; said cam operating a switch 33 interposed in said circuit. The slip coupling shown, comprises the gear 34 which has a large hub 35, free of but in face contact with the friction wheel 36. Said gear is free on the shaft 37, but said Wheel is secured on such shaft. A compression coil spring 38 about the free end of said shaft 37, adjustably anchored by the nut 39, presses the gears hub 35 against the friction wheel 36. For removal of the shaft 30 to replenish the top ply roll thereon, the bearings 40, 40' supporting such shaft, are openable. This shaft has positioning collars as 41 to attain automatic engagement of the gears 29 and 29' when said shaft is mounted in its bearings. Said motor 26 and the system of gears through 29' may be carried on a plate 42 for attachment to the carriage 19 of the machine. A suitable bracket 43 secured to the machine frame, is provided to hold the switch 33. The cam 32 is designed to efiect operation of said motor, from the start to the finish of every stitch line across the work, and to havethe motor circuit open while stitching is done along the work. The cam on the machine which controls operation of the pinch rollers 20, 20', can be used to control the operation of said switch 33.

To make the mesh-form design which is commonly called a box design as shown in FIG. 4, the sewn formation to be effected by each needle 18, is a zig-zag line as AJ in which successive stitch lines as AB and BC, BC and CD, CD and DE, DE and EF, etc., need be in perpendicular relation with the stitch lines AB, CD, EF, etc., along the work and the stitch lines BC, DE, FG, HI, etc., across the work. Heretofore, without my attachment, though the machine 15 was provided with suitable cams on the cam shaft 24, it was necessary to have the carriage 19 at rest while the feed or pinch rollers 20', 20 were rotated to feed the work 44 so the line AB is sewn, then to halt said rollers while the carriage was shifted to the left in FIG. 1 so the line BC was sewn, then while the carriage again held at rest, to operate said rollers so the line CD was sewn and finally to halt said rollers while the carriage was moved to the right so the line DE was sewn, and then to repeat such cycle ad infinitum, the finished work delivered by the machine was as shown in FIG. 5. The corners of the zig-zag lines aa'j, etc., which should have coincided, did not, that is, point 12' was spaced from the point c, point was spaced from point b", etc., and the transverse stitch lines as be, bc' slanted in one direction while the transverse stitch lines as de, de slanted in the opposite direction. This is caused by the relaxation in the tension of the work, occurring at each stoppage of the pinch rollers 20, 20 for sewing across the work and the resulting movement of the work towards the pinch rollers.

It may be noted that in quilting, the stitched designs may be squares or rectangles, the length of a side of which may be from two to six inches. Although the box design is used to explain this invention, those versed in the art will readily recognize that this invention is applicable to any design which includes straight lines of stitching across the work.

So to avoid the distortions shown in FIG. and get the desired design work done properly as shown in FIG. 4, the top ply 21 is prevented from creeping towards the pinch rollers 20, 20 by applying a proper tension thereto during all stoppages of said pinch rollers, for the sewing of transverse stitch lines. This is accomplished by use of the attachment 25, which is automatically operated during all such stoppages, to apply a tension in the top ply, to neutralize the force causing the creep and to tense said top ply in a direction towards the supply roll 21, to give said ply the tension it has from the pull of said pinch rollers when the latter feed the work. Such tensioning is effected by applying a suitable force to turn the supply roll 21 to wind up. This is done by running the motor 26, which through a system of speed reduction gearing as shown in FIG. 3, applies a turning force to the shaft 30 to wind up the roll 21 which is mounted on said shaft so the top ply 21 Will be made taut. The slippage of an adjustable slip coupling 27 interposed in said gear system, maintains such tautness. The cam 32 serves to operate the switch 33 controlling the motor circuit 31, in a proper timed relation so that the motor 26 is powered while all transverse stitch lines are being sewn and deactuated while all stitch lines along the work are being sewn.

While stitching is being done along the work, the rotation of the gear 29 with its shaft 30, will cause its associated two-way turnable gear system to turn the shaft of the motor 26 in a direction opposite to its operating direction. The resistance offered by the gear system and the motors armature will effect a braking action on the shaft 30' while the roll 21 unwinds, which is necessary and usually is supplied by brake means (not shown) on the machine 15. With the use of the attachment 25, such brakes may be of smaller capacity and in some instances entirely dispensed with because the braking action offered by said resistance may be sufficient.

Upon actuation of the motor 26, the roll 21 will wind up,'thus tensing the top ply 21 to neutralize the force causing the said creep as well as to apply normal running tension in the top ply which said ply was subject to while the machine was stitching along the work. The tension effected in said ply is maintained constant because of the slip coupling 27 which is adjusted to allow no greater tension. Said adjustable slip coupling, the gear system it is interposed in and the motor 26 are chosen to suit the particular machine 15 they are used on.

In setting up for a run of work, the machine is operated and its work observed. If the cornering of the design is improper, the slip coupling 27 is adjusted by turning the nut 39 until the sewn design is made proper. Whether the design sewn is or is not correct on the back ply 22', is immaterial, because in most instances it is a cheese cloth. However, if it should be required that the design on the back ply shall be perfectly cornered, another attachment like 25 may be on the carriage 19, for the control of the back ply.

This invention is capable of numerous forms and various applications without departing from the essential features herein disclosed. It is therefore intended and de sired that the embodiment shown herein shall be deemed merely illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claims rather than to the specific showing and description herein to indicate the scope of this invention.

I claim:

1. In an automatic multi-needle sewing machine for quilting a plurality of superposed plies, of the class hav ing a carriage slidably mounted on a frame for movement in a direction transverse to the direction of the feed of the plies, pinch rollers mounted on the carriage for moving the plies past the needles by pulling said plies to unwind the top ply and the bottom ply supply rolls, top and bottom supply roll shafts on the carriage for holding said supply rolls, and a cam shaft on the frame having first cam means thereon for controlling the operation of said pinch rollers and the movement of the car riage, the combination with said carriage of a device for tensioning the top ply comprising an electric motor mounted on the carriage, rotatable means connecting the shaft of said motor and the top ply supply roll shaft for turning said top ply supply roll shaft in a direction to wind up a top ply supply roll when the latter is thereon upon the operation of said motor, a slip coupling interposed in said rotatable means; said top ply supply roll shaft being turnable for a supply roll thereon to unwind while the pinch rollers are operated, a circuit for oper ating said motor, a normally open switch interposed in the circuit and a second cam means secured on said cam shaft adapted to shift and hold said switch in closed condition so said motor will operate during all stoppages in the operation of said pinch rollers while the carriage is in motion to tension the top ply while sewing lines of stitching transverse to the direction of the work feed.

2. A combination as defined in claim 1, including means to adjust said coupling to alter the force required to drive it.

3. A combination as defined in claim 1, wherein the rotatable means comprises a gear secured to the top ply supply roll shaft, a gear secured on the motor shaft and shaft means interconnecting said gears; said slip coupling being interposed in said shaft means.

4. A combination as defined in claim 1, wherein the rotatable means includes a speed reduction means operating whereby the speed of the motor shaft is comparatively high and the speed of the top ply supply roll shaft is comparatively low while the motor is actuated.

5. A combination as defined in claim 1, wherein the rotatable means comprises a gear secured on the top ply supply roll shaft, a gear secured on the motor shaft, first and second shafts journalled on the carriage, first and second gears secured on the first shaft, third and fourth gears secured on the second shaft; the first gear being in meshed relation with the gear on the motor shaft, the second and third gears being in meshed relation, the fourth gear being in meshed relation with the gear on the top ply supply roll shaft.

6. A combination as defined in claim 5, wherein said slip coupling is interposed between the third and fourth gears.

7. A combination as defined in claim 5, wherein the first gear is larger than the gear on the motor shaft, the third gear is larger than the second gear and the gear on 8. A combination as defined in claim 5, wherein there is provided means for removably mounting said top ply supply roll shaft on the carriage.

References Cited UNITED STATES PATENTS PATRICK D. LAWSON, Primary Examiner.

the top ply supply roll shaft is larger than the fourth 15 V- LARKIN, Assistant Examinergear. 

1. IN AN AUTOMATIC MULTI-NEEDLE SEWING MACHINE FOR QUILTING A PLURALITY OF SUPERPOSED PLIES, OF THE CLASS HAVING A CARRIAGE SLIDABLY MOUNTED ON A FRAME FOR MOVEMENT IN A DIRECTION TRANSVERSE TO THE DIRECTION OF THE FEED OF THE PLIES, PINCH ROLLERS MOUNTED ON THE CARRIAGE FOR MOVING THE PLIES PAST THE NEEDLES BY PULLING SAID PILES TO UNWIND THE TOP PLY AND THE BOTTOM PLY SUPPLY ROLLS, TOP AND BOTTOM SUPPLY ROLLS, AND A CAM SHAFT ON THE FRAME HOLDING SAID SUPPLY ROLLS, AND A CAM SHAFT ON THE FRAME HAVING FIRST CAM MEANS THEREON FOR CONTROLLING THE OPERATION OF SAID PINCH ROLLERS AND THE MOVEMENT OF THE CARRIAGE, THE COMBINATION WITH SAID CARRIAGE OF A DEVICE FOR TENSIOINING THE TOP PLY COMPRISING AN ELECTRIC MOTOR MOUNTED ON THE CARRIAGE, ROTATABLE MEANS CONNECTING THE SHAFT OF SAID MOTOR AND THE TOP PLY SUPPLY ROLL SHAFT FOR TURNING SAID TOP PLY SUPPLY ROLL SHAFT IN A DIRECTION TO WIND UP A TOP PLY SUPPLY ROLL WHEN THE LATTER IS THEREON UPON THE OPERATION OF SAID MOTOR, A SLIP COUPLING INTERPOSED IN SAID ROTATABLE MEANS; SAID TOP PLY SUPPLY ROLL SHAFT BEING TURNABLE FOR A SUPPLY ROLL THEREON TO UNWIND WHILE THE PINCH ROLLERS ARE OPERATED, A CIRCUIT FOR OPERATING SAID MOTOR, A NORMALLY OPEN SWITCH INTERPOSED IN THE CIRCUIT AND A SECOND CAM MEANS SECURED ON SAID CAM SHAFT ADAPTED TO SHIFT AND HOLD SAID SWITCH IN CLOSED CONDITION SO SAID MOTOR WILL OPERATE DURING ALL STOPPAGES IN THE OPERATION OF SAID PINCH ROLLERS WHILE THE CARRIAGE IS IN MOTION TO TENSION THE TOP PLY WHILE SEWING LINES OF STITCHING TRANSVERSE TO THE DIRECTION OF THE WORK FEED. 